1.Cooperate with the doctor in the position. The conventional position for dual-energy X-ray bone densitometry is the posterior-anterior lumbar spine position, i.e. 90° of hip flexion. During the examination, the patient should lie flat in the center of the scanning bed and lift both legs up and rest on a square plastic block so that the spine is straight. Patients who are unable to flex their hips at 90° for some reason may be considered for examination in a 45° or straight hip position, i.e. 0° hip flexion; 2. The computer automatically records and analyzes the examination results; 3. The patient arranges his clothes and leaves the operating table.